7998 is an esthetic number in base 6, because in such base its adjacent digits differ by 1.
7998 is an undulating number in base 6.
It is a congruent number.
27998 is an apocalyptic number.
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
7998 is a wasteful number, since it uses less digits than its factorization.
7998 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 79.
The square root of 7998 is about 89.4315380612. The cubic root of 7998 is about 19.9983331944.
Subtracting 7998 from its reverse (8997), we obtain a palindrome (999).
Multiplying 7998 by its reverse (8997), we get a triangular number (71958006 = T11996).
The spelling of 7998 in words is "seven thousand, nine hundred ninety-eight".